There is provided a paper sheet accumulator assembly for successively underlaying paper sheets in good order at a collection station, comprising at least one paddle wheel disposed downstream of a conveyer belt assembly for delivering paper sheets to the accumulator assembly and having a plurality of swirling paddles overlapping with each other, said paddle wheel being carried for rotating to receive paper sheets underside of said paddles such that one paper sheet is inserted under each paddle, an abutting plate disposed adjacently to said paddle wheel for abutting against the leading ends of the paper sheets inserted underside of said paddles, and a kick roller for pushing the paper sheets and kicking the trailing ends of the paper sheets upward to kick out them from the underside of the paddles. The paper sheet accumulator assembly of the invention is suitable for use in a bank note dispenser. Also provided is a bank note dispenser provided with the aforementioned paper sheet accumulator assembly and having two bank note discharge ports provided at the opposed side walls of the frame of the dispenser, whereby a bundle of bank notes may be dispensed from either of the discharge ports selectively as desired.